Advanced manufacturing, also referred to herein as additive manufacturing, may be used to quickly and efficiently manufacture complex three-dimensional components layer-by-layer, effectively forming the complex component. Such advanced manufacturing may be accomplished using polymers, alloys, powders, solid wire or similar feed stock materials that transition from a liquid or granular state to a cured, solid component.
Polymer-based advanced manufacturing is presently accomplished by several technologies that rely on feeding polymer materials through a nozzle that is precisely located over a substrate. Parts are manufactured by the deposition of new layers of materials above the previously deposited layers. Unlike rapid prototyping processes, advanced manufacturing is intended to produce a functional component constructed with materials that have strength and properties relevant to engineering applications. On the contrary, rapid prototyping processes typically produce exemplary models that are not production ready.
In general, advanced manufacturing selectively adds material in a layered format enabling the efficient fabrication of incredibly complex components. Unlike subtractive techniques that require additional time and energy to remove unwanted material, advanced manufacturing deposits material only where it is needed making very efficient use of both energy and raw materials. This can lead to significant time, energy, and cost savings in the manufacture of highly advanced components for the automotive, biomedical, aerospace and robotic industries. In fact, advanced manufacturing is a manufacturing technique in which it may be faster, cheaper, and more energy efficient to make more complex parts. However, wide scale adoption of this technology requires a non-incremental improvement in production rates and component scale.
Conventional polymer extrusion systems typically feed a polymer filament into a liquefier to extrude a material. Existing materials experience expansion upon melting and contraction upon cooling due to their coefficient of thermal expansion (CTE). If a part is manufactured by depositing hot material over cool material, the constrained cooling manifests itself as residual stress which manifests itself as curl and warp. In addition, one specific challenge is that when extruded material is deposited with a nozzle, the material often bulges above the nozzle face. Such bulges in the material, when solidified, interfere with the deposition of subsequent adjacent beads of material. In addition, it is difficult to fill material into a given layer without voids or overfilling.
The subject invention improves the deposition quality of additively manufactured parts by reducing unwanted bulges, voids and geometric errors during deposition. The subject invention is further designed for use within or outside of an oven. In addition, the subject invention may further act to improve layer-to-layer adhesion.